Calculation of share in civil suit

We (me and my sister) are jointly substitute(after expunging of my father and mother) plaintiffs ....and already got expartee preliminary decree ( which is plaintiff is acuared jointly 1/4 th share according to plaint) in the year 2013 ....in the mean time I approached to high court in the 2016 for immediate appointment for commissioner according to preliminary decree..because the case is running for long time..--------high court passed the order in favor of me.....-----according to high court order......commissioner appointment is already done according to preliminary decree in the year 2017.I have submitted the requsite commissioner fees directed by the court....after all the proceedings one plaintiff(my sister) wants separate share and seperate possession ......instead of joint share Joint possesion...... Is it possibe now....????.but I want joint share and joint possession according to preliminary decree.....pls answer my quiries